(1) Field of the Invention
The invention relates to a fixing tool for holding a midsole and a shoetree in the shoe industry, and more particularly to a temporary fixing tool which can be re-used and can minimize the damage upon the shoetree.
(2) Description of the Prior Art
It is well known that shoes play important roles in people daily dressing, yet few know how the shoe is produced. In fact, even a pair of ordinary shoes need complicated manufacturing processes. In the shoe industry, a so-called wooden xe2x80x9cshoetreexe2x80x9d which mimics a foot profile is prepared before a shoe can be made. Then, a shoe can be made in accordance with the contour provided by the shoetree. Therefore, formation of the shoetree is so important that it requires to meet every foot""s need and thereby to form a shoe with great wearing comfort.
Conventionally, a bottom structure of shoe includes at least three layers: an inner sole, a midsole and an outer sole. The inner sole is the upper layer which is generally placed at a final step of manufacturing the shoe. The outer sole is the lowest layer that contacts with the ground. The midsole is the middle layer sandwiched by the inner sole and the outer sole. In manufacturing the shoe, a midsole is firstly nail-fix to a bottom of the shoetree temporarily. Then, a vamp with coarse sewing is fixed to the midsole in accordance with the contour provided by the shoetree. No matter what fixing method (sewing or gluing) is applied to integrate the vamp and the midsole, a sufficient and necessary requirement is that the midsole needs to be stable in position under the shoetree. Generally in the art, nails are usually used to fix the midsole to the bottom of the shoetree. Nevertheless, the nailing method has some obvious disadvantages as follow.
1. After the midsole and the vamp are fixed, the shoetree needs to be removed so that following steps of manufacturing the shoe can be proceeded. That is to say that the nails for fixing the midsole to the shoetree need to be pulled off in advance. It is well known that pulling a nail is generally not an easy job, in particular for those nails that are firmly hammered into the wooden shoetree. At this time, using a nail puller to remove the nail is hard and quite possible will damage the midsole as well as the shoetree.
2. Not only the nail is hard to be removed, but also the pulled nail cannot be re-used which will form a kind of material waste.
3. Repeatedly using the nails at the same positions of the shoetree will definitely damage the shoetree gradually. Therefore, the lifetime of the shoetree is usually short. Yet, unit price for a shoetree is usually high so that substantial cost needs to be invented on replacing the shoetree while manufacturing the shoe.
Accordingly, it is a primary object of the present invention to provide a fixing tool for holding a midsole and a shoetree, which a threaded part is used to replace the conventional nail. The fixing tool of the present invention includes a screw base and a screw body. The screw base is a hollow hob screw with both an outer thread and an inner thread. The screw body is formed by a screw with a flat round head and a turnable screw holder.
While applying the fixing tool in fixing a midsole onto a bottom of a shoetree the screw base is firstly screwed into a proper position at the bottom of the shoetree. Then, the midsole can be placed smoothly onto the bottom of the shoetree. Finally, the screw body is used to penetrate the midsole and fastened to the screw base. After the screw holder is bent aside, the midsole can be temporarily fixed to the shoetree.
After a vamp is fixed to the midsole, the screw holder can be bent to its original upright position and is turned to screw off the screw thereof for relieving the midsole from the shoetree.
By providing the fixing tool of the present invention, the fixing process between the midsole and the shoetree become easily and no harm can be made to the shoetree. Also, the screw body can be always re-used so that the laboring and the cost for manufacturing the shoe can be reduced.
All these objects are achieved by the fixing tool for holding a midsole and a shoetree described below.